Project description:We analysed the transcriptomic signature associated to fast and slow growing microcolonies generated after the encapsulation of single cells belonging to a clonal wild-type population, in alginate microspheres. This allowed us to identify particular gene expression signatures associated to each subpopulation. In particular, we found that slow growing cells display an increased expression of respiratory genes even when growing in glucose rich media.
Project description:In this research, ovalbumin (OVA) and sodium alginate (SA) were used as the materials to prepare an OVA-SA composite carrier, which protected and encapsulated the hydrophobic kaempferol (KAE) and the hydrophilic tannic acid (TA) (OVA-SA, OVA-TA-SA, OVA-KAE-SA, and OVA-TA-KAE-SA). Results showed that the observation of small diffraction peaks in carriers proved the successful encapsulation of KAE/TA. The protein conformation of the composite nanoparticles changed. OVA-TA-SA composite nanoparticles had the highest α-helix content and the fewest random coils, so the protein structure of it had the strongest stability. OVA-TA-KAE-SA composite nanoparticles had the strongest system stability and thermal stability, which might be due to the synergistic effect of the two polyphenols, suggesting the encapsulation of KAE/TA increased the system stability and the thermal stability of OVA-SA composite nanoparticles. Additionally, the composite nanoparticles were endowed with antioxidant ability and antibacterial ability (against Staphylococcus aureus and Escherichia coli) in the order OVA-TA-SA > OVA-TA-KAE-SA > OVA-KAE-SA based on the difference in antibacterial diameter (D, mm) and square (S, mm2), indicating that polyphenols enhanced the antibacterial and antioxidant ability of OVA-SA composite nanoparticles, and the enhancement effect of TA was stronger than that of KAE. These results provide a theoretical basis for the application of OVA-SA composite nanoparticles in the delivery of bioactive compounds.
Project description:Soil-transmitted nematodes (STN) infect 1-2 billion of the poorest people worldwide. Only benzimidazoles are currently used in mass drug administration, with many instances of reduced activity. Terpenes are a class of compounds with anthelmintic activity. Thymol, a natural monoterpene phenol, was used to help eradicate hookworms in the U.S. South circa 1910. However, the use of terpenes as anthelmintics was discontinued because of adverse side effects associated with high doses and premature stomach absorption. Furthermore, the dose-response activity of specific terpenes against STNs has been understudied. Here we used hollow, porous yeast particles (YPs) to efficiently encapsulate (>95%) high levels of terpenes (52% w/w) and evaluated their anthelmintic activity on hookworms (Ancylostoma ceylanicum), a rodent parasite (Nippostrongylus brasiliensis), and whipworm (Trichuris muris). We identified YP-terpenes that were effective against all three parasites. Further, YP-terpenes overcame albendazole-resistant Caenorhabditis elegans. These results demonstrate that terpenes are broad-acting anthelmintics. Terpenes are predicted to be extremely difficult for parasites to resist, and YP encapsulation provides water-suspendable terpene materials without surfactants and sustained terpene release that could lead to the development of formulations for oral delivery that overcome fast absorption in the stomach, thus reducing dosage and toxic side effects.
Project description:The aim of the present work is fabrication of dual cross linked sodium alginate (SA)/montmorillonite (MMT) microbeads as a potential drug vehicle for extended release of curcumin (CUR). The microbeads were prepared using in situ ion-exchange followed by simple ionotropic gelation technique. The developed beads were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (X-RD) and scanning electron microscopy (SEM). The effect of MMT on encapsulation efficiency of CUR and intercalation kinetics was investigated. Dynamic swelling study and in vitro release study were investigated in simulated intestinal fluid (pH 7.4) and simulated gastric fluid (pH 1.2) at 37 °C. Results suggested that both the swelling and in vitro release studies were influenced by the pH of test media, which might be suitable for intestinal drug delivery. The release mechanism was analyzed by fitting the release data into Korsmeyer-Peppas equation.
Project description:BackgroundHuman amniotic epithelial cells (hAECs) exhibit a strong capability to restore ovarian function in chemotherapy-induced premature ovarian failure (POF). However, the therapeutic efficacy of hAECs is usually affected by the limited number and proliferative ability of grafted hAECs in target organs. The transplantation of stem cells encapsulated in sodium alginate-bioglass (SA-BG) composite hydrogel has recently been shown to be an effective strategy for tissue regeneration. The current study aims to investigate the therapeutic potential of hAECs or hAEC-derived conditioned medium (CM) encapsulated in SA-BG in mice with chemotherapy-induced POF.MethodsC57BL/6 mice were intraperitoneally injected with chemotherapy drugs to induce POF. hAECs or CM were harvested and encapsulated in SA-BG composite hydrogel, which were transplanted onto the injured ovaries of mice with POF. Follicle development, granulosa cell function, and ovarian angiogenesis were evaluated by morphological methods. To further elucidate the effect of SA-BG-encapsulated hAECs/CM on vascularization, the tube formation of human umbilical vein epithelial cells (hUVECs) was conducted in vitro. Cytokine array and ELISA were used to analyze and quantify the effects of bioactive components released by SA-BG on the secretion of angiogenic factors by hAECs.ResultsThe transplantation of SA-BG-encapsulated hAECs/CM restored follicle development, repaired granulosa cell function, and enhanced ovarian angiogenesis in POF mice. The further study showed that SA-BG significantly promoted the tube formation of hUVECs in vitro. Moreover, encapsulating hAECs could facilitate the effect of SA-BG on inducing the formation of the capillary tube in a paracrine manner. In addition, we found that SA-BG extracts significantly enhanced the viability of hAECs and stimulated the secretion of pro-angiogenic factors of hAECs. Notably, compared with SA-BG/CM, SA-BG/hAECs achieve better therapeutic effects, possibly because stimulation of BG enhanced the viability and paracrine capacity of hAECs.ConclusionsThe present study initially demonstrates that SA-BG-encapsulated hAECs or CM can exert a therapeutic effect on chemotherapy-induced POF mainly by protecting granulosa cell function and enhancing ovarian vascularization, which might provide a novel strategy for the delivery of hAECs for treating POF.
Project description:Carbohydrate-binding modules (CBMs), as an important auxiliary module, play a key role in degrading soluble alginate by alginate lyase, but the function on alginate gel has not been elucidated. Recently, we reported alginate lyase VxAly7B containing a CBM32 and a polysaccharide lyase family 7 (PL7). To investigate the specific function of CBM32, we characterized the full-length alginate lyase VxAly7B (VxAly7B-FL) and truncated mutants VxAly7B-CM (PL7) and VxAly7B-CBM (CBM32). Both VxAly7B-FL and native VxAly7B can spontaneously cleavage between CBM32 and PL7. The substrate-binding capacity and activity of VxAly7B-CM to soluble alginate were 0.86- and 1.97-fold those of VxAly7B-FL, respectively. Moreover, CBM32 could accelerate the expansion and cleavage of alginate gel beads, and the degradation rate of VxAly7B-FL to alginate gel beads was threefold that of VxAly7B-CM. Results showed that CBM32 is not conducive to the degradation of soluble alginate by VxAly7B but is helpful for binding and degradation of insoluble alginate gel. This study provides new insights into the function of CBM32 on alginate gel, which may inspire the application strategy of CBMs in insoluble substrates.
Project description:In the present study, a hybrid microsphere/hydrogel system, consisting of polyvinyl alcohol (PVA)/sodium alginate (SA) hydrogel incorporating PCL microspheres is introduced as a skin scaffold to accelerate wound healing. The hydrogel substrate was developed using the freeze-thawing method, and the proportion of the involved polymers in its structure was optimized based on the in-vitro assessments. The bFGF-encapsulated PCL microspheres were also fabricated utilizing the double-emulsion solvent evaporation technique. The achieved freeze-dried hybrid system was then characterized by in-vitro and in-vivo experiments. The results obtained from the optimization of the hydrogel showed that increasing the concentration of SA resulted in a more porous structure, and higher swelling ability, elasticity and degradation rate, but decreased the maximum strength and elongation at break. The embedding of PCL microspheres into the optimized hydrogel structure provided sustained and burst-free release kinetics of bFGF. Besides, the addition of drug-loaded microspheres led to no significant change in the degradation mechanism of the hydrogel substrate; however, it reduced its mechanical strength. Furthermore, the MTT assay represented no cytotoxic effect for the hybrid system. The in-vivo studies on a burn-wound rat model, including the evaluation of the wound closure mechanism, and histological analyses indicated that the fabricated scaffold efficiently contributed to promoting cell-induced tissue regeneration and burn-wound healing.
Project description:D1 multipotent mesenchymal stromal cells (D1‐MSCs,ATCC® CRL 12424TM) and genetically modified with the lentiviral vector pSIN‐EF2‐Epo‐Pur to express erythropoietin (EPO). D1‐MSCs genetically modified to release EPO were immobilized into 3D alginatepoly‐ L‐lysine‐alginate (APA) microcapsules. Since different formulations of alginate 1.5%, poly‐L‐lysine 0.05%, alginate 0.1% and washings were designed, two types of APA microcapsules were obtained: Biological microcapsules (made of Biological formulations) and Technological microcapsules (made of Technological formulations). The expression of the cells under different conditions of these two types of microcapsules have been analyzed. The present analysis proved that the mechanical properties of the matrix in which cells are enclosed influences drastically gene expression
Project description:Current treatment options for adrenal insufficiency are limited to corticosteroid replacement therapies. However, hormone therapy does not replicate circadian rhythms and has unpleasant side effects especially due to the failure to restore normal function of the hypothalamic-pituitary-adrenal (HPA) axis. Adrenal cell transplantation and the restoration of HPA axis function would be a feasible and useful therapeutic strategy for patients with adrenal insufficiency. We created a bioartificial adrenal with 3D cell culture conditions by encapsulation of bovine adrenocortical cells (BACs) in alginate (enBACs). We found that, compared with BACs in monolayer culture, encapsulation in alginate significantly increased the life span of BACs. Encapsulation also improved significantly both the capacity of adrenal cells for stable, long-term basal hormone release as well as the response to pituitary adrenocorticotropic hormone (ACTH) and hypothalamic luteinizing hormone-releasing hormone (LHRH) agonist, [D-Trp6]LHRH. The enBACs were transplanted into adrenalectomized, immunodeficient, and immunocompetent rats. Animals received enBACs intraperitoneally, under the kidney capsule (free cells or cells encapsulated in alginate slabs) or s.c. enclosed in oxygenating and immunoisolating ?Air devices. Graft function was confirmed by the presence of cortisol in the plasma of rats. Both types of grafted encapsulated cells, explanted after 21-25 d, preserved their morphology and functional response to ACTH stimulation. In conclusion, transplantation of a bioartificial adrenal with xenogeneic cells may be a treatment option for patients with adrenocortical insufficiency and other stress-related disorders. Furthermore, this model provides a microenvironment that ensures 3D cell-cell interactions as a unique tool to investigate new insights into cell biology, differentiation, tissue organization, and homeostasis.
Project description:Lysine acetylation is a dynamic posttranslational modification with a well-defined role in regulating histones. The impact of acetylation on other cellular functions remains relatively uncharacterized. We explored the budding yeast acetylome with a functional genomics approach, assessing the effects of gene overexpression in the absence of lysine deacetylases (KDACs). We generated a network of 463 synthetic dosage lethal (SDL) interactions involving class I and II KDACs, revealing many cellular pathways regulated by different KDACs. A biochemical survey of genes interacting with the KDAC RPD3 identified 72 proteins acetylated in vivo. In-depth analysis of one of these proteins, Swi4, revealed a role for acetylation in G1-specific gene expression. Acetylation of Swi4 regulates interaction with its partner Swi6, both components of the SBF transcription factor. This study expands our view of the yeast acetylome, demonstrates the utility of functional genomic screens for exploring enzymatic pathways, and provides functional information that can be mined for future studies.